I too am experiencing this issue although I cannot seem to determine a pattern. Not sure if the device is rebooting or simply waking from sleep. I may go hours without using the device and it fires immediately. Other times after as little as 30 minutes of being idle, the device displays the welcome screens as you described. The device also does not always seem to recognize when a new coil is present. Sometimes it does, other times it does not. This also seems to be very random...